Anterior-throttled carbureter.



E. P. NOYES.

ANTERIOR THROTTLED CRBUBETBR.

urmoulox FILED une, 190s.

993,097.- l Patenteamay'z. 19uv UNITED STATES PATENT oEEICE.

EDWARD P. BSTOYES, 0F WINCHEBTEVR, MASSACHUSETTS, ASSIGNOR, BY IVIESNE ASSIGN- 'ME-Nl'S. TO C. P. POWER COMPANY, 0F NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.'

To all whom it may concern:

' Bc it lince-n that I, EDWARD P. Novas, a citizen oit the. United States, residing at Winchester in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Am teriorflln-otficd Carbureters, of which the following is a'sl'ieciic'ation,

This irmntion relates to aspiratin or liquid-fuel entraining carbureters suc Vas are ordina -y placed on the suction side of an interna :cnibustion motor and operated by the passage of the air-current caused by the pumping action of the motor.

Heretofcre it has been customary tle the mixture going to the engine by means of an externally-controlled valve located osterior to 'the mixingchamber .of the car? meter-that is, on the outlet side of saidy mixing chamber, between 1t and the engins-but such valves have certain disadvantages including a tendency to throw down or separate a portion of the aspirated fuel in liquid form,'especially at low airvelocities, and inferior suction in the mixing chamber whenl the motor is performing slm-vl and. the throttlepartly closed, besides ,wll l.: they ordinarily have no provisionfor maintaining' combustible proportions inthe mi aturc when tlieaiiusupply to the mixingchamber below atmospheric pressure` The latter condition may exist when motor Asuction is applied to uses outside of the car` bnreting function, an example of such outside use being here'nafter described and claimed, and a' further example being de scribed and claimed in my Fatent' Non 979,788, dated December 27,1919.'

The object. of my present 'invention isto. avoid these disadvantages, and 1;; accom l1sh `the same by ein loying an anterior t rottlc-that is, one ocated on the 4air-inlet side of the 'mixing' chamberwandepintrolli the ainsupply which goesA to theiifiixing-c amber, in place of the usual posteriori throttle, together with `suitable means for maintaining the air and fuel in combustible ropertons ai, all degrees of mixingamber vacuum'. ln connection therewith I may provide an additional air-inlet, suitably controlled, whixr'eby the'motor suctioncan be aiplied to some outside'p se, suchas lifting. the fuel to -supply t c carbureter reservoir.

l The accompanylngdrawing represents :ai

. Specification o! Letters Patent.

to throt-f Vin combustible proportion. The form of the` Patented May 23,"1911.,

Application led Hay 6, 1908. Serial No. 431,088.

sectional diagrammatic view of a carburetor and fuel-supply apparatus embodymg my invention an constructed on the open-jetv or U-tube plan where the constant-level reservoir and jet-nozzle form two legs of a U.

.mixing-chamber 2 with an out et 3- lea to the motor and an air-inlet 4 controlle by a throttle valve 5 which has an o erating lever 6 adapted t0 be connected wit a gov`- ernor or with amanual o r similar operating device adjustable at will. This throttle.- valve is thus located on the air-inlet side f; .the mixing chamber and constitutes the pri., mary agent for controlling the motor by* varying ,the density of an `air-and-fuel charge, While its ingredicntsare maintained throttle-valvem'ay b e varied but it should et 1 1s the air and mixture pi e havirg a preferably be a quick-acting device"adjiisi-I .g 'i

.able from its open to its closed position' vice versa by a relativelyshortmovement of i the controlling connections, it 'being in this respect similar to an ordinary mixture throttle-valve.

7 is a float chamber or reservoir'with float 8 and valve 9 and a suction-lift jet-nozzle 10 rising to an outlet in the mixing chamber 2, said jet-nozzle andthe walls of the surrounding air-passa e constituting a. -fuelaspirating device apted tobe operated by motor suction, all in the usual forni 'except that the float chamber is not normally under atmospheric pressure. I l have omitted to show the needlevalve which is frequentl employed to control the jet-nozzle, butth'is device, having either a normally-fixed ad-4 justment or being automatically adjustable '1n any known or suitable manner may be employed in connection .with my invention. l

In order; .to keep the air and fuel in comf 'bustible'l 'roportions at'all degrees'o mix?- ing-charn er vacuum it is desirable to employ in cqrmectioxr'with the anterior throttle some mealsfor maintaining a working preponderance of air-pressure in the floatchamber4 at all openingsof the .throttlevalve, and this pressure-differencebetween float-chamber and mixing-chamber should .preferably remain substantially constant,- though a slight departure from constancy will not 'destroy thc combustibilit of the mixture and may at times be desirable lin l order'to'net the requirements of the motor. `I- contemplate various expediente withm' abs? i scope of the invention and have selected a preferred. means for illustration as follows. Through a vacuum pipe or duc-t 11 connecting the top of the float chamber with a 5 chamber 19 immediately .posterior to the throttle-valve 5, I establish, in the space above the fuel in said fioat chamber, the vacuum imposed by said valve (or it may be some derivative vacuum varying conformably With the throttle-imposed vacuum).

To create apressure down-drop between the chamber19 and the mixingchamber 9. I provide between said chambersyan air-oonstricting device which, in the form here shovvn7 is a check valve 12 seated by a light wspring 13 of adjustable tension. Any suitable equivalent for this device, not necessarily includingan automatic moving part, may be employed. The .spring check-valve 2.0 lf2 or its equivalent in combination with means such as the pipe 11 for transmitting the throttle-imposed vacuum to the rear surface of the fuel constitutes a means for maintaining the fuel and air in combustible proportions throughout the range of the throttling device. If additional impulseon the fuel is desired in starting or at other Atimes it may be had by opening a small valve let controlling an atmospheric air inlet-pipe loleading to the float chamber 7 or an ad` ditional. impulse may be obtained by.

strengthening or tightening the spring 13, so asi'to create an increased pressure-dierence between Heat-chamber .and mixingchamber.l

40 tive tendency of the fuel by removing air pressure from its surface, but it also makes available a stronger impelling force on the fuel than is attained With posterior-throttled carbureters. As the throttle-valve does not .45 obstruct the mixture-passage therevis nol resulting tendency to' mechanically separate a portion of the fuel'from the air after leaving the mixing-chamber.

Thisinvention, furthermore, enables me to I( employ, the engine vacuum for extraneous purposeswvIti may-be used-V for example to lift the fuel through a'pipe 16 from asnitable' source of supply into an yelevated tank 17. The lattenfcan be sealed air-tight and 5-5 connected by4 a pipe 1'8 with the' vacuum pipe 11 and the-chamber 19 posterior to-throttle 5. When valve 2() in'pipe l16 and 'valve 4Q1 in pipe "18 areo'p'ened thc engine suction will cause atmospheric pressure at the main stre of fuel supply 'to'force the fuel up into tank 17'. When the-latter is full,a sevid"en'ced by' a gage 22, valve 20 is closed. Fuel descends by gravity from tank 17 into float chamber *I f;

rough a pipe 23 past float valve 9.. Then employing a fioat valve in the reservoir 7, I may embody the tank 1-7 as a permanent feature of the fuelsupply system for the* carbureter and Jleave the valve 21 open. The partial vacuum in tank 17, which is `the same as that in float chamber 7, then avoids an Vexcessive pressure tending to force fuel past the float valve 9.v I may however employ v any suitable constant-level device in place of thefloat valve and retain the tank 17 in connectiony therewith. Tank 1.7 may be tbe main fuel tank in theA supply system for the carbureteror it may be a local tank periodically filled. Variations of this illustratcd arrangement are obviously permitted. For example, since I have made available the difference between atmospheric pressure and motor-vacuum pressure as an' agency for ,lifting the fuel to the carbureter, it would 4be possible to altogether omit a. gravity-feed of "fuel, or a super-atmospheric pressure feed such as is sometimes employed, and connect the carburetor supply pipe directly'to any suitable supply tank at a lower level than the carbureter, though not so loeT as to .eX- ceed the lifting power of saidl pressuredif ference. The equivalent .of such arrangement would be realized by leaving valve 2() permanently open and shutting valve 21,

valve 25 being also closed.

l 24 is a* pipe connected with chambeixl) and containing a stop-valve 26 whereby the engine vacuum may when desired be applied to other 'outside purposes. In my Patent No. 979,788, aforesaid is illustrated the use of explosiveengine vacuum for dust-collection, and mypresent carbureter and fuelsupply system can be employed in connection with the apparatus there shown or other vacuumfusing apparatus.

It will be'unoerstood however that the carbureter is not exclusively confined to operation at air-pressures from and belowthe atmospheric, since its principle of construc leve of the jair-supply,"which is not true of .the o dinary carburetor with a float-chamvWorking preponderance of air pressure in the fuel reservoir at all degrees of mixingchamber vacuum, as this subject-matter is described and .claimed in my earlier application, SeriaINoBQQOO, tiled June 29, 1906,

"inyapresent carbureter being aspecific form of the invention thus designated.

.claixn" f Y, 1. In' a liquid-fuel carbureter, the combination of a-niixing-cliamber having an air-v inlet passage, a throttle-valve Vcontr'ollii'i'gl said passage, a constant-level fuel-reservoir tion makes it independent of the -pressurehaving an outlet to said mixingchamber of normally-constant aperture, and means for maintaining a substantially-constant di'erenoe of air-pressure between said fuel reservoir and mixingfchamber throughout the operation of the carbureter.

2. In a liquid-fuel carbureter, thevcornbirv nation of a mixing-chamber having an airinlet passa e, a throttle-valve adjustable to open and o ose said passage, a spring-seated check-valve in the air-passage between the throttle .valve and the mixing-chamber, a

fuel reservoir havin a fuel-outlet to said mixing-chamber, an Y aV vacuum duet oonnecting theup er part of'said fuel-reservoir with the air-in et passa e ata oint between the throttle-valve and t e chec -valve.

3. In a liquid-fuelcarbureter, the combination of a miXig-chamber having an airinlet passage, a-'throttle-valve adjustable to ,open and close said passage, a spring-seated check-valve in the airpassage between the throttlej valve and the miX1ng-chamber,.a fuel-reservoir having a fuel-outletto said mixing-chamber, a vacuum duct connectingV said fuel-reservoir with the air-inlet passage between the throttle-valve and the oheek-valve, and a valve-controlled atmos-` pheri'o air inlet to said reservoir.

4. In avapor carbureter operated by motor suction, the combination of means to supply liquid fuel, means for aspiratingthe fuel by-th'e passage of the suction air-current, two air-inlet passages' for supplying air to theraspirating means, a throttle-valve in one of the air-in1et passages, anvadjustableV stopvalve in theother air-inlet passage, and means for maintaining the air and fuel in `combustible proportions throughout the range of said valves.

5'. A' liquiduel oarbureter comprising air-andfuel mixing mea-ns, throttling means for controlling the air-sup ily anterior to the mixing point, a constant evel reservoirfor supplying fuel to the mixlng means, means for causing -the airpressure in said reservoir pressure, and means for applying the vacuum imposed by said throttle-va v ply-fue .to said reservoir from a-'lower level.

mixing-chamber having an ,air-inlet passage, a throttle-valve adjustable to o en and close said passage, a constant-levell uel reservoir having a fuel-outlet to said mixingohamber,

of air-pressure in said reservoir at all degrees of mixing-chamber vacuum', a branch conduit entering theiair-inlet' assage at la point between the throttle-va ve and the mixing-chamber for applying the oarbureter vacuum to an outside purpose, and a stopvalve controlling said branch conduit.

' 7. A carbureter comprising a, mix-in chamber, a fuel-reservoir havinga jet-nozz e rising to an outlet in said chamber, a floatvalve to maintain a constant level in said gravity feed to said reservoir past the floatvalve and provided with a suction-lift fuelinlet pipe, a stolp-valvein said pipe, anan.- terior -air-thrott e controlling the vacuum in.

throttle vacuum in said reservoir, and means to establish the throttle vacuum at will in said tank.

the mixture density by throttli-ng the 'airfto the mixing point, and means for lifting -the fuel 'from asource of su plyto or above the'level ofV the carbureter l; difference due to the motor vacuum.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses,` the 4th day nf .May, 1908.

' Witnesses: f P. W. Pazzam,

E. BATGHELDER;

to vary conformably with the throttled 'aire to sup- 6. A liquid-fuel carbureter comprisin'ga means to maintain a Working preponderance supply .of said carbureter at a point anterior reservoir, an elevated sealed tank having a'.

said mixing-chamber, means to'establish the 8. A` motor carbureting .and fuellifting i i systemcompri'sing a suetion-operatedigelaspirating oarbureter, means for controllingy the pressure- EDWARD P. ANoires. 

